Python-symbolic/python_symb/expr.py
2023-08-02 00:39:13 +02:00

38 lines
945 B
Python

from __future__ import annotations
from tree import Tree
from operator_file import Add, Mul
from operator_file import UnaryOperator, BinOperator
from typing import List
from symbols import Var
from parse import infix_str_to_postfix
class Expr(Tree):
def __init__(self, value, children=None):
super().__init__(value, children if children else [])
@staticmethod
def from_postfix_list(postfix: List):
def aux():
first = postfix.pop()
match first:
case int() | Var():
return Tree(first)
case UnaryOperator():
return Tree(first, [aux()])
case BinOperator():
return Tree(first, [aux(), aux()])
return aux()
@staticmethod
def from_infix_str(expr_str):
expr_rev_polish = infix_str_to_postfix(expr_str)
return Expr.from_postfix_list(expr_rev_polish)